1. Field of the Invention
The present invention relates to a novel washing agent. More specifically, it relates to a detergent composition for domestic or business use or a skin cleanser composition comprising one compound or two or more compounds selected from compounds having a protease inhibitory activity, which prevents and ameliorates skin irritation, and at the same time, is harmless to the human body and has a strong washing power.
2. Description of the Related Art
Washing compositions such as cleansers and detergents have been generally employed for removing contaminates or soils attached to the surface or internally of materials and the human body, and may be broadly classified into 1) those used for the human body, 2) those used for clothing and fiber products, 3) and those for washing soft and rigid surfaces.
Among these cleansers, the cleanser for the human body (i.e., skin) is intended to remove the fat and sweat secreted from the skin surface, and other corneum cells detached as a result of metabolism (i.e., dirt), outside contamination attached thereto, and cosmetics.
The surfactant contained in a detergent is a chemical exhibiting a washing power and foaming power which are inherent properties of the detergent, but these are known to have an adverse influence on human skin. A detergent which comes directly into contact with human skin must produce only a weak irritation of the skin or eyes.
For skin cleansers, surfactants with a low irritation effect have been developed to obtain useful products, but there remains a need to improve the washing power and foaming power thereof.
For the washing of the human body, surfactants with a low irritation, effect have been developed to obtain useful products, but there remains a need to improve the washing power and foaming power, and a product which fully satisfies users has not yet been developed. Further, even though the composition has a low irritation effect, it would be more useful if a chemical which treats and ameliorates skin irritation were formulated therein.
On the other hand, currently, for washing objects other than the human body, the surfactants primarily used have a strong washing power but also cause an irritation of the skin or eyes. Although efforts to improve safety have been made by working with the use of protective tools such as gloves, or by way of after-care after completion of the work, the sensitivity of the fingertips may be lost depending the work, and thus the wearing of gloves may be unsuitable in some cases; sometimes skin irritation is reported to be generated by the gloves per se. Also, although the practice of after-care after the completion of work is is important, it is considered more useful if the chemical acts during the work.
Many proteases are known to exist, which maintain the structure and constancy of the skin functions, and the important role thereof thus recently attracted more attention. A protease or proteolytic enzyme is the comprehensive name for enzymes which catalyze a peptide bond by hydrolysis, and such proteases are classified into peptidases and proteinases. The former are enzymes which cleave the peptide bond from the outside of the amino group terminal end or the carboxyl group terminal end of a protein or a peptide chain, and the latter proteinase are enzymes which cleave the specific bond internally of a peptide chain. Such proteinases are known as "protease" in a broad sense, and further, are broadly classified, according to the properties of their active sites, into 1) serine type, 2) thiol (cysteine) type, 3) carboxyl type and 4) metal proteinase, and specific inhibitors exist for the respective enzymes.